Twin Castle 1717 Truggy project

[brainanator]

Can't wait to see videos of this thing if you ever film it. Going be some kind of monster, that's for sure.

[Lizard]

A little progress.


Mounted a wing and a wheeliebar using the ST-1 Pro wingmount. Somehow I don't like the look of these high-downforce wings, need to search for something with a more "classic" look.

Wheeliebar is from an MT4G3, it's compatible with the ST-1 Pro wingmount and fits niceley through the Savage bumper.

Painted and trimmed the body. With only 185g it's quite light for the size. As it already worked well with my Slash, securing of the body to the chassis will be done using velcro.

Then I finally started making the chassis tray, took me a while to decide on material and how to make it. Material is HDPE, it's light, slippery, strong and can be welded using a heatgun. Now the complete underside except for the (flush) aluminum plate in the middle is covered with plastic. Next step is to weld 2 inch high sidewalls to the plastic bottom plate to make it a tray.

[Manne]

Keep going! What a MONSTER!

[Lizard]

Manne:
Yeah, my trigger finger is already itching, hope I'll get it running before the weather gets too bad :)


Chassis Tray is done and seems to be pretty solid. Welding the PE with the heatgun turned out to be not too hard. It doesn't look too good, but considering that this was my first time welding something, I'm happy. Should keep the dirt out and protect everything on the chassis.

Made a chassis brace from 10mm CFK tube that connects to the front and rear diffhousings/bulkheads. The rear plastic block on the brace also acts as a brace for the wingmount.

Front and center diff are now shimmed and filled. Front 30.000 cst, center 2.000.000. Since I did the rear diff half a year ago, I don't remember what I filled in, I think it's 20.000 or 30.000 :)

[Manne]

I love the looks of carbonfiber, but I have never used it on any of my trucks, maybe it´s time to use it on my new truck.

What cases are those that the cen diff sits in?

[Lizard]

Those are GPM cases for the old (non-X) Savage. Last time I have used them was 2007 on my Nitro Savage.

[phildogg]

Should be plenty of power, Truck looks great.

[Lizard]

Thanks :) Yeah, I hope that thing will rip seriously.


Now it's nearing finished state.

Chassis tray and chassis brace are now on the car. Then made another brace using Savage hinge-pin braces from the wingmount to the aluminum profile in the rear. Chassis seems very stiff now. Batteries are strapped to the chassis with two big straps that go between the chassis-tray and the chassis-plate.


Wired up the ESCs and plastidipped everything. Wiring is not really clean, will do this later. As a switch I used an 8-pin socket/plug, this switches both ESCs, the BEC and the 24V on simultaneously. For testing purposes I made two extra plugs that allow to switch on the ESCs seperately.

The BEC is a 7A 5.5V Hobbyking BEC, Servo is Savox SA-1283SG with 300Ncm at 6V. Without extra capacitor, there are glitches when moving the servo fast, with capacitor it seems to be okay.

Wires are all 0,5qmm silicone wires and the plus and minus rails on the Traxxas TQI receiver habe been re-inforced with copper and solder to make sure the servo gets enough power.

As you can see, the ESCs are now right next to the motors, this way they can be cooled by the same 80mm 24V fans that cool the motors.


RTR Weight as on the picture with 225g PMT 1/5 scale GT tires is quite exactly 8kg or 17.6lbs.
Theoretical topspeed is 78mph now with 3.7V per cell, 4.72 inch tires, 46/20 gears and 2.888 CEN diffs.

The Mamba Monster startup beep sequence is "polyphonic" now, sounds cool :)
Did a quick testrun in my home on tiles. It cogged a little. Gave it more throttle, now I have some black rubber marks on my tiles. Feels really powerful already. Need to test it outside.

[Lizard]

Yay, it's running :)


Went through two battery sets, no crashes or damages so far. Did not dare to go full throttle, because it was pulling to the side when accelerating hard, need to check if everything is setup 100% exact.

The PMT 1/5 scale GT tires worked quite well with the 8Kg car, far better than with my 5.4Kg 1717 Truggy, although I think it's not perfect yet. Could not get them warmer than 35 Celsius. Maybe I should try the GRP 1/5 scale tires, they are said to be less dependent on temperature.

Handling is quite good for my taste, but the steering is sloppy, the plastic servo mount flexes too much, need to make a more rigid mount.

The motor ran good, with gearing for 125kph maximum temp was about 40C (with 20C ambient temp). ESCs and batteries were even below that temp.

Sound is also very nice for my taste, quite loud for an electric-powered car :)


Here is a short video of the first run:
[youtube]tnB3zRuVEeE[/youtube]

[lilpanther]

That's one of the coolest thing's I have seen in a long time. The sound of that is awesome with it being that loud. How do you like the HobbyKing BEC?

[Lizard]

Thanks :)

The Hobbyking BEC seems to work fine. Only thing that's strange is, that I needed a glitchbuster capacitor, I would have thought that external BECs don't need this. On the other hand, Savox servos are known to draw lots of current and the Servo is very strong, so maybe it's normal (?).

[coolhandcountry]

Looks good!
Keep messing around and you be flying in no time. :D

[Lizard]

Finally ran it again and made a video :)
Will post more info later.

[YOUTUBE]wmRFF8hRKhc[/YOUTUBE]

[_paralyzed_]

Very cool. That thing really moves!

[phildogg]

Looks quick! plenty of power on tap..